Over the years, our laboratory has made significant and fundamental contributions to the understanding of Hirschsprung disease (HSCR), and we continue to do so through a currently funded MERIT award that focuses on gene discovery using genetics and genomics. Nevertheless, our research is severely hampered by small sample sizes, non-representative patient recruitment, incomplete phenotypic/clinical data, and difficulties in obtaining access to tissues, since most cases are self-referrals. As we advance from the genetic epidemiological and molecular descriptions of HSCR to potential clinical applications, we will require larger numbers of extensively phenotyped representative patients with corresponding tissue samples. To enable this transition for the HSCR basic and clinical research communities, we are proposing a supplement to the currently funded award to expand our fourth aim of data and sample collection. We have recently formed the Hirschsprung Disease Research Collaborative (HDRC), an organization of geneticists, pediatric surgeons, pathologists and gastroenterologists to capitalize on HDRC members' areas of expertise, and direct patient access, to create a phenotype-genotype-tissue resource. Our specific aims for this revision are: (1) to increase patient sample size and diversity for genomic studies; (2) to collect standardized phenotype data under uniform protocols; and, (3) to develop a high quality collaborative phenotype and tissue repository. The overall goal of this proposal is to build and maintain a well-documented resource, open to all HDRC members, that will not only improve our ability to use modern genomic techniques to carry out the existing aims of the MERIT award, but to further advance fundamental understanding of HSCR through an intellectual and resource collaboration of diverse experts in the field.